Feed mechanism for sewing machines



May 14, 1963 R. REI-:BER ETAL 3,089,445'

FEED MEcHANzsM FOR SEWING MACHINES Filed June 9, 1960 5 Sheets-Sheet 1 ifa May 14, 1963 R. REEBER ErAL FEED MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 2 Filed June 9. 1960 May 14, 1953 R. REEBER Erm. 3,089,445

FEED MECHANISM FOR SEWING MACHINES Filed June 9, 1960 5 Sheets-Sheet 3 May 14, 1963 Filed June 9, 1960 R. REEBER ETAL FEED MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 4 May 14, 1963 R. REEBER Erm.

FEED MECHANISM EoR SEWING MACHINES 5 Sheets-Sheet 5 Filed June 9, 1960 United States Patent O FEED MECHANISM FR SEWING MACHINES Rudolf Reeber and Reinhold Dobner, Kaiserslautern,

Pfalz, Germany, assignors to G.M. Pfaff A.G., Kaiserslautern, Pfalz, Germany Filed June 9, 1960, Ser. No. 34,937 Claims priority, application Germany June 29, 1959 6 Claims. (Cl. 112-208) The invention relates to feed mechanism for sewing machines and more par-ticnlarly to intermittently operating vfeed mechanism for sewing machines of the type used for producing shirring.

For the purpose of producing shirring or crimping by means of sewing machines, the machines are provided with an auxiliary feed bar provided with intermittent feed means in addition to the conventional main material feed bar. Normally the two feed bars eifect synchronous coinciding feeding operations. If the material being sewn is to be crimped or -shirred, the two material feed bars are made to effect feed movements of different magnitude. For this method of operation the auxiliary feed bar which is arranged -ahead of the stitch position as seen in the direction of sewing must, besides covering the required feed distance for shirring of the one layer of material, also cover the same distance which Athe main feed bar -which is provided behind the auxiliary bar must cover for moving the `sewed layers of material. Long Shir-ring distances require thrust movements of the auxiliary feed bar of such length that it is possible to sew only relatively slowly.

The feed driving members moving in the same direction cause undesired oscillation phenomena which result in increased wear of the driving elements.

It is an object of the invention to eliminate these shortcomings and to provide feeding mechanism which permits rapid operating velocities without the incidence o f oscillations. In accordance with the invention this problem is solved in that the operating phases of the material feed members are `displaced with respect to one another in such a manner that the operating movements of the second material feed bar which is separate from the conventional material feed bar and which executes rectangular movements coincide with the ineffective phase of the course of operations. It is possible to employ as feeding elements either two material feed bars arranged below the material carrier plate as well as also one fee-d bar eifective from above and la feed bar arranged in the support plate. It is also possible to provide other combinations of intermittently operating material feed bars.

The two material feed bars are suitably connected for operation with adjustment means, the ycams of which have the same angular velocities, while the eccentric portions of the cams in operating position are displaced by 180 with respect to one another.

Further features of the invention and details of the advantages attained thereby -will become apparent from the following description of the embodiments of the new feeding mechanism illustrated in the accompanying drawings -in which:

FIG. 1 shows a longitudinal section of an embodiment of the invention in a sewing machine having a needle and upper .and lower feed means;

FIG. 2 is a section along line II-II of FIG. l;

FIG. 3 is a section along line III- III of FIG. 2;

FIG. 4 is a section along line IV-IV of FIG. 2;

FIG. 5 is a section along line V--V of FIG. l1;

FIG. 6 is a -side view of the machine with the head cover removed and in which the material carrying plate is shown in section;

FIG. 7 is a section along the line VII--VII of FIG. 1;

and

A means Patented May 14, 1963 FIG. 8 is a perspective view of another embodiment of the feeding mechanism in a sewing machine provided with rrain and auxiliary feed bars below the material carrying p ate.

The machine in accordance with the embodiment of FIGS. 1 to 7 is provided with the conventional material carrier plate 1, a standard 2, an arm 3, and the machine head 4. The horizontally disposed arm shaft 5 is rotatably disposed in the arm 3 where it extends longitudinally of the Aarm and carries at the outwardly extending end the balance wheel A6. At the other end of the shaft'S the arm crank 7 carrying the crank stud -8 is secured which by means of link 9 is connected to the needle bar |10 which moves up and down longitudinally and 'which carries the needle 11 at its lolwer end. The needle bar 10 is journalled in bores of the needle bar oscillator 12 which is suspended at its upper end in the head 4 of the machine on a bearing stu-d 13. The bearing axle of the needle bar oscillator 12 which is defined by the stud 13 extends parallel to arm shaft 5 so that the needle bar oscillator 12 is enabled to effect oscillatory movements in a plane extending perpendicularly to the longitudinal extent of arm 3.

In order to form double stitches the needle 11 cooperates with the catcher 14. The catcher z14 is driven in the conventional manner by the arm shaft 5 by way of the pinion gear pair 15, 16 and shaft 17 disposed vertically in the standard 2 which by way of pinions 118, 19 rotates the catcher drive shaft 20A journalled in the carrier or work plate 1. Mounted at the forward end of drive shaft 20 is a pinion 21 which cooperates with a pinion 22 on the vertical catcher shaft 23 to which the catcher 14 is secured.

The material being sewn is advanced at the stitch forming location by a compound needle, upper and bottom feeding mechanism, while at the same time the needle and the upper material feed bar effect equally directed movements but the lower material feed bar effects movements directed oppositely to the direction of material feed.

For the purpose of imparting feeding movements to the needle 11 the crank `arm 24 is connected with the needle bar oscillator 12, which arm is carried by one end of the needle advancing shaft 25 journalled in arm 3, parallel to -the arm shaft 5. A bifurcated member 26 is clamped to lthe other end of needle advancing shaft 25 the jaws 27 of which are operatively connected to an eccentric stitch setting member 23 of a type known in the art.

FIGS. 2, 3 and 4 show the eccentric or cam stitch setting device 28 with the disk 29 which is connected to arm shaft 5 by a stud screw 30. The disk 29 is surrounded by a setting ring 31 which has a lateral portion provided with the eccentric inner race 32 against which rest the two arms 33 of a cross-headed cam support 34.

The cam support 34 and the setting ring 31 `are held together with the disk 29 by means of stud screws 35 and the slotted apertures 36 in the arms 37 permit sliding adjustment of the cam support 34 relative to the disk 29. The setting ring 31 is secured by means of the annular llange 3S against axial displacement between the disk 29 and the .arms 33 and 37. For the purpose of dening the direction of displacement of the cam support 34 vertically with respect to the shaft 5 for adjusting the magnitude of rocking movement of the needle advancing shaft 25, the disk 29 is provided with grooves 39 which are engaged by corresponding guiding members 40 on arms 33.

The distance of the advancement of the needle and upper feeding means is adjusted by applying pressure to button 41 (FIG. 1) while simultaneously turning the balance wheel 6. The stud 42 then enters the bore 43 of the setting ring 31 to turn the same `relative to the disk 29 which is rigidly Iconnected with arm shaft 5. The cam carrier 34 (FIGS. 2, 3 and 4) and with it also the cam or eccentric 44 which is securely fastened to said carrier is thereby displaced diametrically with respect to arm shaft 5 as a result of the engagement of the arms 33 with the eccentric inner race 32 of the lateral part of the setting ring 31 and the guidance provided between guide members 40 and grooves 39, so that the forked member 26 the jaws .27 of which are disposed about the ring 45 which in turn is disposed around the cam or eccentric 44, will upon rotation of arm shaft 5 impart rocking movements of different magnitude to the rocking shaft 25, depending on the amount of displacement of cam or eccentric 44, and thereby to the needle bar oscillator 12 with which it is connected.

A setting device 46 (FIG. 5) of known type serves for producing the feeding movements of the lower material feed bar. For this purpose a cam or eccentric 47 is secured to the arm or drive shaft 5 which is enclosed by a joint member 50 comprising upper and lower portions 48 and 49 and which is connected with the forked end of rod 52 by way of the joint stud 51. The forked rod 52 is provided with a rotatably journalled cylindrical sliding member 53 which is mounted for sliding movement in the connecting link 55 extending through the jaws of the guide bar 54, which is in turn rotatably secured to a lug 56 on the standard 2 and connected for changing the magnitude of advancing steps from the outside through the slot 57 in the standard 2 by means of the bar 58 extending from the standard. For manual operation the length adjusting bar 58 is provided with a knob 59. At the lower end of the forked bar 52 a crank 60 is provided which is clamped to the material feed shaft 61 under the material carrier plate 1. The connecting link 55 is drawn by means of a helical spring 62 into its ineffective end position until the knob 59 abuts the lower edge of the setting plate 63 which covers the slot 57.

At the forward end of the material feed shaft a crank 64 (FIG. 6) is secured to which a support bar 65 for one lower material feed member is linked.

The eccentric 47 (FIG. 5) of the setting mechanism '46 is arranged .at such an angular position with respect to the eccentric 44 of the stitch setting means 28 that the eccentricity of both eccentrics (44, 47) is displaced by 180. In this manner an alternate movement of the two material feed dogs in the direction of advancement is obtained. The lower feed dog 66 receives its lifting movement from a cam 67 which is secured to the catcher drive shaft 20, the cam bar 68 being in engagement with said cam and linked at its free end to a crank 69. The crank 69 is secured to a material feed shaft 70 disposed parallel to material feed shaft 61 below the material support plate 1 and imparts thereto the rocking movements which originate with the cam 67. A crank 71 (FIG. 6) is provided at the forward end of the material feed or lifting shaft 70 which has a sliding member 72 which slides in the jaws 73 of the support bar 65 and imparts lifting movements to the lower material feed dog 66.

The upper feed mechanism has an upper material feeding device or feed member 74 which is secured to the lower end of the axially movable upper feed bar 75 which is supported in the needle bar oscillator 12 which imparts feeding movements to the needle bar as well as to the upper feed bar 75.

A ca m or eccentric 76 (FIG. 7) secured to arm or drive shaft 5 imparts raising movements to the upper material feeding device or feed member 74 by way of a cam rod 77. The free end of the cam rod 77 is secured by means of a wing nut 78 in the arcuate slot 79 of a crank arm 80 which is fastened to the shaft 82 journalled in a lug 81 on machine arm 3. A crank arm 83 (FIG. 6) clamped to the other end of the shaft 82 is connected by means of a link 84 to one arm 85 of an angular lever 86 the other arm 87 of which is operatively connected to the upper feed bar 75.

At the lower end of a presser bar 90 vertically mounted in the machine head a presser foot 89 is secured and a spring 91 yieldingly presses said bar downwardly in a conventional manner. A lifting member 92 is secured to presser bar and presents a stud 93 to which the angular lever 86 is rotatably secured, permitting in the conventional manner the alternating up and down movements of the upper material feed member and of the presser foot 89.

An intermediate or separating plate 94 (FIG. l) is provided for separating the lower one of two layers of material from the upper layer during shirring operations, and is securely fastened to a support 96 pivotally mounted by means of a screw on the material or work plate 1. Arr angular member 97 secured to the material carrier or work plate 1 is provided with an adjusting screw 98 by means of which the raised position of the intermediate plate can be adjusted.

In accordance with the invention the lower layer of material is pressed against the separating plate 94 by the lower feed dog 66 operating in front of the needle 11 through slots in the stitch plate 99 and is advanced, while the upper layer of material rests and the upper feed elements perform their return movements. This results in stacking of the lower material layer to form a pleat directly at the stitch forming location. As the needle 11 enters the pleat thus formed is fixed in its position relative to the smooth or ilat upper material layer and simultaneously both material layers are seized by the upper material feed member 74 and are in cooperation with the needle 11 advanced by one stitch length and sewn. During the return of the upper material feed member 74 and of the needle 11 the next shirring of the lower material layer takes place.

The stitch length is determined by the magnitude of the feed movement of the upper material feed member 74 and of the needle 11 adjusted by the stitch setting cam means 28, while the shirring length of the lower layer of material is adjusted by setting the length of the feed advancement of the lower feed bar and dog 66 by means of the setting device 46 from zero to a maximum.

FIG. 8 shows another embodiment of the feeding mechanism in accordance with the invention in a sewing machine which has neither upper feeding means nor needle bar feeding means. The drive for the feed movements corresponds to that in accordance with FIG. 5. Here the two feed dogs which effect movements in opposite directions are arranged below the work plate of the sewing machine, while the main feed dog 101 which determines the stitch length and its driving components are of known construction.

The main feed dog 101 is secured to the bar 102, the rearward end of which is linked to the crank arm 103 which is supported on the forward end of the material feed shaft 104 which imparts rocking movements thereto. A stitch adjusting device for this arrangement may be in the form of the construction of the setting device 46 illustrated in FIG. 5 which has an eccentric 47 on shaft 5 linked by way of member 50 and forked bar 52 to the crank 60 which is clamped to the feed shaft 104 as seen in FIG. 8.

The lifting movements are imparted to the main feed dog 101 in a known manner by a cam 67 on the catcher drive shaft 20 of the machine (FIG. 5) which imparts feeding movements by way of bar 68 and crank 69 to the lifting shaft 109. The lifting shaft 109 which is journalled parallel to the feed shaft 104 carries at its forward end the crank 110. The sliding member 111 which is carried -by the crank 110 slides in the jaws of the forked bar 112 of the bar 102 and transmits the movements of the crank 110 thereto.

The auxiliary feed dog l113 is secured to a support 114 which engages with the jaws of its forked end 115 a sliding member 116 which is provided at the end of a crank 117. The crank 117 is clamped to the rocking shaft 109 in such a manner that the sliding member 116 is disposed in front of a ver-tical plane which extends through the axis of the material feed shaft 109, while the slide member 111 of the crank 110 is arranged rearwardly of this plane. In this manner opposite lifting movements are imparted to the two sliding members 111 and 116 during the rocking of shaft 109 and thereby to the two feeding devices 101 and 113.

The feeding movements of the auxiliary feed dog 113 are derived from the material feed shaft l104 by way of a setting device 11'8 which is clamped by means of a support member or crank means 119 to the material feed shaft 104. The support mem-ber and crank means 119 has a slide bar 120 which slidingly guides a stud 123 disposed in a bore 121 of a lever 122. The lever 122 is journalled on a shaft 124 which is loosely carried by a link 125 mounted on the feed dog raising shaft 109; A link 126 connects the other end of the shaft 124 to the supporting arm 114 of the auxiliary feed dog 113. The support arm or bar =111- is supported at its rearward end at operating level by a crank 127 which is likewise loosely supported on the feed shaft 104.

Feeding movements 'are imparted to the auxiliary feed dog 113 as well as to the main feeding device or feed dog 101 by the stitch setting mechanism (not illustrated) whereby, depending on the stitch length, the support member and crank means 119 of the setting device 118 is displaced to a smaller or greater extent. The support member I119 is arranged on the material feed bar 104 in such a manner that alternate feeding movements of the two feed dogs 101 and 113 are effected. In order to additionally increase or decrease the shirring length with respect to the `sti-tch length for which the device is set, it is possible with a draw bar 128y which may be operated manually or by means of a foot pedal which enengages a connecting link of a lever 129 loosely carried on the material feed or lifting shaft 109' and a link 130, to displace the slide member 123 on the slide bar `120` journalled in the bore 121 of lever 122. The slide member 123 is withdrawn to its ineffective end position by a spring 131 which is in engagement with the connection of the link 130 with lever 122.

The shirring effected with the embodiment last described corresponds to that of the first with the difference that for feeding means two lower material feed dogs are employed instead of an upper land a lower feed means.

Having now described our invention with reference to the embodiments illustrated and described, we do not wish to be limited thereto but what we desire to protect by Letters Patent of the United States is set forth in the appended claims.

We claim:

l. A feeding mechanism for sewing machines having a drive shaft and a needle bar supporting a needle operatively connected to lone end of said drive shaft, said mechanism including a main feeding device mounted in operative relationship to the lower end of said needle bar and an auxiliary intermittently operative feed dog disposed in operating proximity to said main feeding device, means including a first eccentric means operative to impart a phase of normal feeding movements to said main feeding device and actuating means operative to impart a phase of feeding movements to said auxiliary feed dog during the inoperative condition of said main feeding device, said actuating means comprising said drive shaft, a second eccentric means mounted on said drive shaft, a rockable feed shaft having a portion operatively linked to said second eccentric means and a crank porti-on connected to said auxiliary feeding device to impart thereto feeding movements initiated at said drive shaft.

2. A feeding mechanism for sewing machines having a drive shaft 'and a needle bar supporting a needle operatively connected to one end of said drive shaft, said mechanism including a main feeding device mounted in operative relationship to the lower end lof :said needle bar and an auxiliary intermittently operative feed dog disposed in operating proximity to said main feeding device, means including a -rst eccentric means operative to impart a phase of normal feeding movements to said main feeding device and actuating means operative to impart a phase of feeding movements to said `auxiliary feed dog during the inoperative condition of said main feeding device, said actuating means comprising said drive shaft, a second eccentric means mounted on said drive shaft, a rockable feed shaft having a portion openatively linked to said second eccentric means and a crank portion connected to said auxiliary feeding device to impar-t thereto feeding movements initiated at said 'drive shaft, said first eccentric means and said second eccentric means including separate adjusting means land being movable with said drive shaft at equal angular velocities and each said first and said second eccentric means having an eccentric portion yand said eccentric portions being displaced at an angle of substantially relative .to one another.

3. A feeding mechanism for sewing machines having a drive shaft and a needle bar supporting a needle operatively connected to one end of said drive shaft, said mechanism including a main feeding device mounted in operative relationship to the lower end of said needle bar and an auxiliary intermittently operative feed dog disposed in operating proximity to said main feeding device, means including a rst eccentric means operative to impart a phase of normal feeding movements to said main feeding device and actuating means operative to impart a phase of feeding movements to sai-d auxiliary feed dog during the inoperative condition of said main feeding device, .said actuating means comprising said drive shaft, a second eccentric means mounted on said drive shaft, a rockable feed shaft having a portion operatively linked to said second eccentric means and a crank portion connected to said auxiliary feeding device to impart thereto feeding movements initiated at said drive shaft, said first eccentric means and said second eccentric means including separate adjusting means and being movable with said drive shaft at equal angular velocities and each said first and said second eccentric means having an eccentric portion Iand said eccentric portions being -displaced at an angle of substantially 180 relative to one ano-ther, and said machine having a Work plate and said feed shaft being supported rearwardly of and below said work plate, and a lifting shaft supported within the forward end and below said work plate, and said lauxiliary feed dog being yoperatively linked to :said feed shaft and to said lifting shaft, and said main feeding device comprising lan upper bar supporting a feed mem-ber disposed 'above said auxiliary `feed dog and linked to said first eccentric means.

4. A feeding mechanism for sewing machines Ihaving a drive shaft, a needle bar operatively connected to one end of said drive shaft, and a needle supported by said needle bar, said mechanism including a main feeding device disposed in operative relationship to the said needle, and an auxiliary intermittently operative feed dog disposed in operating proximity to said main feeding device, means connected to said drive shaft and .to said main feeding device operative to impart a phase of feeding movements to said main feeding device, and operating means connected intermediate said drive shaft and said auxiliary feed dog operative to impar-t a phase of feeding movements to said auxiliary lfeed dog during the inoperative condition of said main feeding device, said machine having a Work plate and sai-d operating means including a rockable feed shaft mounted below and rearwardly of said work plate and crank means connected between said feed shaft and said auxiliary feed dog.

5. A feeding mechanism for sewing machines having a drive shaft, a needle bar operatively connected to one end of said drive shaft, and a needle supported by said needle bar, said mechanism including a main feeding device `disposed in operative relationship to the said needle, and an auxiliary intermittently operative feed dog disposed in operating proximity to said main feeding device, means connected to said drive shaft and to said main feeding device operative to impart a phase of feeding movements to said main feeding device, and operating means connected intermediate said drive shaft and said auxiliary feed dog operative to vimpart `a phase of Ifeeding movements to said auxiliary feed dog during the inoperative condition `of said main feeding device, said machine having ya work plate and said operating means including a rockable feed shaft mounted below and rearwardly of said work plate and crank means connected between said feed shaft and said auxiliary feed dog, and said main feeding device being a feed dog supported on a feed bar and mounted adjacent said iauxiliary feed dog and said feed bar being connected to said shaft by means of a crank arm, and said crank arm being mounted to move in a direction opposite to the direction of movement of said crank means.

6. A feeding mechanism for sewing machines having a drive shaft and a needle bar supporting a needle operatively connected to one end of said drive shaft, said mechanism including a main feeding device mounted in operative relationship to the lower end of said needle bar, and an auxiliary intermittently operative fee-d dog disposed in operating proximity to said main feeding device, means connected to said drive shaft and to said main feeding device operative to impart a phase of feeding movements to said main -feeding device, and operating means connected intermediate said drive shaft land said auxiliary feed dog operative to impart a phase of feeding movements to said auxiliary feed dog during the inoperative condition of said main Ifeeding device, said machine having a work plate and said operating means including a rockable feed shaft mounted below and `rearwardly of said work plate and crank means connected between said feed shaft and said auxiliary `feed dog, and said main feeding device comprising an eccentric mounted on said drive shaft, an upper bar disposed substantially parallel to said needle bar and supporting a feed member above and adjacent to said auxiliary feed dog and operatively linked to said eccentric References Cited in the le of this patent UNITED STATES PATENTS 1,823,505 ONeill Sept. 15, 1931 2,322,207 Hale June 22, 1943 2,377,777 Hale June 5, 1945 2,509,596 Hale et al. May 30, 1950 2,838,018 Herbst June l0, 1958 2,982,241 Fugita May 2, 1961 

1. A FEEDING MECHANISM FOR SEWING MACHINES HAVING A DRIVE SHAFT AND A NEEDLE BAR SUPPORTING A NEEDLE OPERATIVELY CONNECTED TO ONE END OF SAID DRIVE SHAFT, SAID MECHANISM INCLUDING A MAIN FEEDING DEVICE MOUNTED IN OPERATIVE RELATIONSHIP TO THE LOWER END OF SAID NEEDLE BAR AND AN AUXILIARY INTERMITTENTLY OPERATIVE FEED DOG DISPOSED IN OPERATING PROXIMITY TO SAID MAIN FEEDING DEVICE, MEANS INCLUDING A FIRST ECCENTRIC MEANS OPERATIVE TO IMPART A PHASE OF NORMAL FEEDING MOVEMENTS TO SAID MAIN FEEDING DEVICE AND ACTUATING MEANS OPERATIVE TO IMPART A PHASE OF FEEDING MOVEMENTS TO SAID AUXILIARY FEED DOG DURING THE INOPERATIVE CONDITION OF SAID MAIN FEEDING DEVICE, SAID ACTUATING MEANS MOUNTED ON SAID DRIVE SHAFT, A SECOND ECCENTRIC MEANS MOUNTED ON SAID DRIVE SHAFT, A ROCKABLE FEED SHAFT HAVING A PORTION OPERATIVELY LINKED TO SAID SECOND ECCENTRIC MEANS AND A CRANK PORTION CONNECTED TO SAID AUXIALIARY FEEDING DEVICE TO IMPART THERETO FEEDING MOVEMENTS INITIATED AT SAID DRIVE SHAFT. 